Some microelectromechanical systems (MEMS) sensor devices include tethers connecting a resonator or movable proof mass to a substrate. The tethers provide a restoring force when the proof mass is displaced from its equilibrium. The tethers themselves exhibit a degree of stiffness, resisting motion of the movable proof mass. Tethers also can be characterized by their resonance frequencies, which can include a fundamental flexural mode frequency and a multitude of higher harmonic mode resonance frequencies.